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arXiv · 1006.2014

Modulation of pairing interaction in Bi$_2$Sr$_2$CaCu$_2$O$_{8+\delta}$ by an O dopant: a density functional theory study

Kateryna Foyevtsova·H. C. Kandpal·Harald O. Jeschke·S. Graser·H. -P. Cheng·Roser Valentí·P. J. Hirschfeld
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Abstract

Scanning tunneling spectroscopy measurements on the high temperature superconductor Bi$_2$Sr$_2$CaCu$_2$O$_{8+\delta}$ have reported an enhanced spectral gap in the neighborhood of O dopant atoms. We calculate, within density functional theory (DFT), the change in electronic structure due to such a dopant. We then construct and discuss the validity of several tight binding (TB) fits to the DFT bands with and without an O dopant. With the doping-modulated TB parameters, we finally evaluate the spin susceptibility and pairing interaction within spin fluctuation theory. The d-wave pairing eigenvalues are enhanced above the pure system without O dopant, supporting the picture of enhanced local pairing around such a defect.

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Kateryna Foyevtsova, H. C. Kandpal, Harald O. Jeschke, S. Graser, H. -P. Cheng, Roser Valentí, P. J. Hirschfeld. 2010-06-10. Modulation of pairing interaction in Bi$_2$Sr$_2$CaCu$_2$O$_{8+\delta}$ by an O dopant: a density functional theory study. https://doi.org/10.1103/physrevb.82.054514

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